package sectoraccessor

import (
	"context"
	"io"

	"golang.org/x/xerrors"

	"github.com/filecoin-project/lotus/api"
	"github.com/filecoin-project/lotus/api/v1api"
	"github.com/filecoin-project/lotus/chain/types"
	sectorstorage "github.com/filecoin-project/lotus/extern/sector-storage"
	"github.com/filecoin-project/lotus/extern/sector-storage/storiface"
	"github.com/filecoin-project/lotus/markets/dagstore"
	"github.com/filecoin-project/lotus/node/modules/dtypes"
	"github.com/filecoin-project/lotus/storage/sectorblocks"

	"github.com/filecoin-project/go-address"
	"github.com/filecoin-project/go-fil-markets/retrievalmarket"
	"github.com/filecoin-project/go-state-types/abi"
	specstorage "github.com/filecoin-project/specs-storage/storage"

	"github.com/ipfs/go-cid"
	logging "github.com/ipfs/go-log/v2"
)

var log = logging.Logger("sectoraccessor")

type sectorAccessor struct {
	maddr address.Address
	secb  sectorblocks.SectorBuilder
	pp    sectorstorage.PieceProvider
	full  v1api.FullNode
}

var _ retrievalmarket.SectorAccessor = (*sectorAccessor)(nil)

func NewSectorAccessor(maddr dtypes.MinerAddress, secb sectorblocks.SectorBuilder, pp sectorstorage.PieceProvider, full v1api.FullNode) dagstore.SectorAccessor {
	return &sectorAccessor{address.Address(maddr), secb, pp, full}
}

func (sa *sectorAccessor) UnsealSector(ctx context.Context, sectorID abi.SectorNumber, pieceOffset abi.UnpaddedPieceSize, length abi.UnpaddedPieceSize) (io.ReadCloser, error) {
	return sa.UnsealSectorAt(ctx, sectorID, pieceOffset, 0, length)
}

func (sa *sectorAccessor) UnsealSectorAt(ctx context.Context, sectorID abi.SectorNumber, pieceOffset abi.UnpaddedPieceSize, startOffset uint64, length abi.UnpaddedPieceSize) (io.ReadCloser, error) {
	log.Debugf("get sector %d, pieceOffset %d, length %d", sectorID, pieceOffset, length)
	si, err := sa.sectorsStatus(ctx, sectorID, false)
	if err != nil {
		return nil, err
	}

	mid, err := address.IDFromAddress(sa.maddr)
	if err != nil {
		return nil, err
	}

	ref := specstorage.SectorRef{
		ID: abi.SectorID{
			Miner:  abi.ActorID(mid),
			Number: sectorID,
		},
		ProofType: si.SealProof,
	}

	var commD cid.Cid
	if si.CommD != nil {
		commD = *si.CommD
	}

	// Get a reader for the piece, unsealing the piece if necessary
	log.Debugf("read piece in sector %d, pieceOffset %d, startOffset %d, length %d from miner %d", sectorID, pieceOffset, startOffset, length, mid)
	r, unsealed, err := sa.pp.ReadPiece(ctx, ref, storiface.UnpaddedByteIndex(pieceOffset), startOffset, length, si.Ticket.Value, commD)
	if err != nil {
		return nil, xerrors.Errorf("failed to unseal piece from sector %d: %w", sectorID, err)
	}
	_ = unsealed // todo: use

	return r, nil
}

func (sa *sectorAccessor) IsUnsealed(ctx context.Context, sectorID abi.SectorNumber, offset abi.UnpaddedPieceSize, length abi.UnpaddedPieceSize) (bool, error) {
	si, err := sa.sectorsStatus(ctx, sectorID, true)
	if err != nil {
		return false, xerrors.Errorf("failed to get sector info: %w", err)
	}

	mid, err := address.IDFromAddress(sa.maddr)
	if err != nil {
		return false, err
	}

	ref := specstorage.SectorRef{
		ID: abi.SectorID{
			Miner:  abi.ActorID(mid),
			Number: sectorID,
		},
		ProofType: si.SealProof,
	}

	log.Debugf("will call IsUnsealed now sector=%+v, offset=%d, size=%d", sectorID, offset, length)
	return sa.pp.IsUnsealed(ctx, ref, storiface.UnpaddedByteIndex(offset), length)
}

func (sa *sectorAccessor) sectorsStatus(ctx context.Context, sid abi.SectorNumber, showOnChainInfo bool) (api.SectorInfo, error) {
	sInfo, err := sa.secb.SectorsStatus(ctx, sid, false)
	if err != nil {
		return api.SectorInfo{}, err
	}

	if !showOnChainInfo {
		return sInfo, nil
	}

	onChainInfo, err := sa.full.StateSectorGetInfo(ctx, sa.maddr, sid, types.EmptyTSK)
	if err != nil {
		return sInfo, err
	}
	if onChainInfo == nil {
		return sInfo, nil
	}
	sInfo.SealProof = onChainInfo.SealProof
	sInfo.Activation = onChainInfo.Activation
	sInfo.Expiration = onChainInfo.Expiration
	sInfo.DealWeight = onChainInfo.DealWeight
	sInfo.VerifiedDealWeight = onChainInfo.VerifiedDealWeight
	sInfo.InitialPledge = onChainInfo.InitialPledge

	ex, err := sa.full.StateSectorExpiration(ctx, sa.maddr, sid, types.EmptyTSK)
	if err != nil {
		return sInfo, nil
	}
	sInfo.OnTime = ex.OnTime
	sInfo.Early = ex.Early

	return sInfo, nil
}